DESCRIPTION

The DS18B20X Digital Thermometer provides 9 to 12–bit centigrade temperature measurements and has an alarm function with nonvolatile user-programmable upper and lower trigger points. The DS18B20X communicates over a 1-wire bus that by definition requires only one data line (and ground) for communication with a central microprocessor. It has an operating temperature range of –55°C to +125°C and is accurate to ±2.0°C over the range of 0°C to +70°C. In addition, the DS18B20X can derive power directly from the data line (“parasite power”), eliminating the need for an external power supply.

FEATURES

• Unique 1-wire interface requires only one port pin for communication

• Each device has a unique 64-bit serial code stored in an on-board ROM

• Multi-drop capability simplifies distributed temperature sensing applications

• Requires no external components

• Can be powered from data line. Power supply range is 3.0V to 5.5V

• Measures temperatures from –55°C to +125°C (–67°F to +257°F)

• ±2.0°C accuracy from 0°C to +70°C

• Thermometer resolution is user-selectable from 9 to 12 bits

• Converts temperature to 12-bit digital word in 750 ms (max.)

• User-definable nonvolatile alarm settings

• Alarm search command identifies and addresses devices whose temperature is outside of programmed limits (temperature alarm condition)

• Applications include thermostatic controls, industrial systems, consumer products, thermometers, or any thermally sensitive system